Radon is a toxic, colorless, odorless gas. It is produced during the radioactive decay of uranium and is naturally present in soil and rocks in many parts of the country. Exposure to high levels of radon greatly increases the risk of developing lung cancer, especially for smokers. Radon may enter water supplies or buildings from adjacent soils and rock. Average outdoor radon levels are about 1.3 picocuries per liter of air. Buildings with an annual average of 4 picocuries per liter or more are considered to have elevated radon levels. All Forest Service buildings must be tested for the presence of radon gas, and those with elevated radon levels must be modified to reduce the level below 4 picocuries per liter.

This section is under construction. Please check back later for more information. Meanwhile, check out the Washington Office Engineering FSWeb section on radon (Web site available only to FS and BLM employees) for some web links that provide more information.

Map courtesy of E.O. Lawrence Berkeley National Laboratory's High-Radon Project , Phillip N. Price, Anthony Nero, Kenneth Revzan, Michael Apte, Andrew Gelman, W. John Boscardin, and others.